A touch sensor may detect the presence and location of a touch or the proximity of an object (such as a user's finger or a stylus) within a touch-sensitive area of the touch sensor overlaid on a display screen, for example. In a touch sensitive display application, the touch sensor may enable a user to interact directly with what is displayed on the screen, rather than indirectly with a mouse or touch pad. A touch sensor may be attached to or provided as part of a desktop computer, laptop computer, tablet computer, personal digital assistant (PDA), smartphone, satellite navigation device, portable media player, portable game console, kiosk computer, point-of-sale device, or other suitable device. A control panel on a household or other appliance may include a touch sensor.
There are a number of different types of touch sensors, such as (for example) resistive touch screens, surface acoustic wave touch screens, and capacitive touch screens. Herein, reference to a touch sensor may encompass a touch screen, and vice versa, where appropriate. When an object touches or comes within proximity of the surface of the capacitive touch screen, a change in capacitance may occur within the touch screen at the location of the touch or proximity. A touch-sensor controller may process the change in capacitance to determine its position on the touch screen.
In some aspects of touch-sensor technology, touch sensors that detect touch input include bond pads. Bond pads provide an interface to one or more component that process signals detected by touch sensors (e.g., dual-sided sensors), such as flexible printed circuits (FPC). Aspects of such components (such as a bond area of an FPC) have been placed between touch sensors and the screen itself and, as a result, have led to certain problems. One such problem is that moisture ingress may occur due to gaps being present between the screen and the touch sensor. Another problem that may arise is that multiple bonding operations must be performed when coupling dual-sided touch sensors to components like an FPC causing increased expense. Yet another problem that may arise is that bonding a dual-sided sensor to a component such as an FPC may cause creases that can damage touch sensors.